How Diverticular Disease Is Diagnosed

Diverticular Disease Might Not Always Require a Diagnosis

In most cases, diverticular disease doesn't cause symptoms. Diverticulosis is the formation of diverticula, which are small, usually painless pouches that can develop in the colon. And diverticulitis, which is diverticular inflammation, can cause discomfort or pain. These conditions tend to occur after the age of 40.

When diverticular disease is asymptomatic, it is often discovered as an incidental finding, such as with a screening colonoscopy. Tests that might be done to evaluate symptoms of possible diverticular disease include a non-invasive abdominal computed computerized tomography (CT) scan or a colonoscopy, which is more invasive.

polyps removal
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A colonoscopy is a diagnostic test that is done to look inside the large intestine, which is also called the colon. Food that hasn’t been fully broken down in the small intestine is further processed in the colon before it is eliminated through the rectum and the anal canal.

Starting at the age of 45 years, it’s recommended that people who are at average risk for developing colon and rectal cancer have screening colonoscopies at regular intervals. This diagnostic procedure can identify diverticular disease. it can also identify a polyp, which may be a precursor to colon cancer. Polyps that are found during a colonoscopy are usually removed so they won't progress to becoming cancerous cells.

Preparing for the Test

During a colonoscopy, a colonoscope, which is a long tube with a light and a camera on the end, is inserted up through the anus. Some steps are taken for preparation in the days prior to a colonoscopy.

It’s important for the colon to be clear of any stool so that the healthcare provider completing the test can have an unobstructed look at the wall of the colon. This involves a colonoscopy preparation, or prep, and is usually considered the more challenging part of the entire procedure.

Colonoscopy prep includes:

  • Strong laxatives that may be given in liquid or pill form, and sometimes in combination.
  • In some instances, an enema might also be used.
  • Fasting before the test is necessary. A diet of clear liquids is prescribed the afternoon before the test, and then nothing to eat or drink after midnight the night before the test.

You will have an IV line started prior to your colonoscopy. Your medical team will use this so you can receive fluids and sedating medications. When your procedure is complete, the sedatives will be stopped and you will wake up and be monitored for a short time.

It’s not safe for you to drive right after your test because of the sedatives, so a friend or family member will need to drive home. After resting and taking it easy for the rest of the day, most people can return to their regular schedule the next day.

Obtaining Results

You may need a follow-up appointment with your healthcare provider to talk about the results of your test. If any diverticula were found during your colonoscopy, your healthcare provider will discuss plans for treatment, which can include dietary or lifestyle changes.

If you've had a polyp removed or a biopsy taken during your colonoscopy, these tissues will be tested in the laboratory for signs of cancer.

Abdominal CT Scan

Diverticular disease may also be diagnosed with an abdominal CT scan. This test might be used to evaluate possible diverticular disease, especially if a colonoscopy is not recommended due to pain or bleeding.

An abdominal CT scan is a painless and non-invasive test that produces an image of the abdomen. You would need to fast for a few hours prior to the test to for better visualization of the colon.

What to Expect

The test will usually take about 30 minutes, depending on how many images are needed.

Contrast dye is used so that abdominal structures show up better on the final images. For an image of the colon, the dye will be given both as a drink and in an IV. The drink will be given prior to the start of the test.

Obtaining Results

After your CT scan, any necessary follow-up will be individualized based on the results of your test and your overall health. In some cases, the test is being done to assess diverticulitis and also to assess the possibility of other conditions that may be causing the symptoms. 

If there are diverticula found in the colon, but they’re causing no symptoms, you might not need treatment. If you have diverticultis, a treatment plan will be needed right away because of the acute nature of this condition.

7 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Salzman H, Lillie D. Diverticular disease: diagnosis and treatmentAm Fam Physician. 2005;72(7):1229-1234.

  2. NIH National Institute of Diabetes and Digestive and Kidney Diseases. Colonoscopy.

  3. Destigter KK, Keating DP. Imaging update: acute colonic diverticulitis. Clin Colon Rectal Surg. 2009;22(3):147-55. doi:10.1055/s-0029-1236158

  4. Barroso AO, Quigley EM. Diverticula and Diverticulitis: Time for a Reappraisal. Gastroenterol Hepatol (NY). 2015;11(10):680-8.

  5. Harvard Health Publishing Harvard Medical School. Preparing for a colonoscopy.

  6. Cleveland Clinic. Colonoscopy: test details.

  7. NIH US Department of Health and Human Services. Computed tomography (CT).

Additional Reading
  • American Society of Colon and Rectal Surgeons. "Diverticular Disease." 2018.
  • Harvard Men's Health Watch. "Diverticular disease of the colon.” Harvard Health Publishing. 5 Dec 2015.  
  • Tursi A, Papa A, Danese S. "Review article: the pathophysiology and medical management of diverticulosis and diverticular disease of the colon.&rdquo Aliment Pharmacol Ther. 2015;42:664-684. doi: 10.1111/apt.13322.

By Amber J. Tresca
Amber J. Tresca is a freelance writer and speaker who covers digestive conditions, including IBD. She was diagnosed with ulcerative colitis at age 16.